It has been observed that infection arising from the presence of invasive and/or implanted medical devices in the human body can be ascribed to at least two distinct sources. Firstly, bacteria may pass from the skin down the outside of the medical device, for example a catheter or cannula. However, there is a second source of potential infection and that is via the interior of the medical device itself. For example, poor clinical technique may allow contamination to occur at a point in the equipment remote from the position of entry of the device to the body and a subsequent liquid flow in the device, such as an injection, can transfer the bacteria into the body.
It is an object of the present invention to provide a novel medical device, wherein this second potential source of infection is combatted by providing a positive electrical field remote from the operative end of the device, preferably out of the liquid flow path through the device. Under normal physiological conditions, the bacteria associated with mammals carry a net negative charge and are therefore attracted by said positive electrical field, away from the operative end of the device.